IMO he’d be much better served going with a Modkita so he could run at 30,000 PPM instead of being limited to 10,000 RPM!
For quiet (when not cutting), he might want to consider a high speed water cooled HF spindle like this one.
It looks like the Nomad motor’s maximum speed is likely ~3k RPM - so a 60k ERPM limit probably isn’t a problem.